Self contained breathing apparatus



Filed April 25, 1957 2 Sheets-Sheet FIG.

I I'BIH N R a m T N s E N u W A R B A x 2; 9 2

gul

Sept. 29, 1959 M. A. BRAUNSTEIN 2,906,262

SELF CONTAINED BREATHING APPARATUS Filed Apl il 25', 1957 2 Sheets-Sheet 2 FIG- 4 I M. A. BRAUNST'EIN v' v INVENTOR United States Patent SELF CONTAINED BREATHING APPARATUS Melvin A. Braunstein, Wilmerding, Pa.

Application April 25, 1957, Serial No. 655,121

Claims. (Cl. 128-142) This invention relates to improvements in breathing apparatus of the closed-circuit type adaptable particularly for use in underwater swimming, exploration and salvage work.

The main object of the present invention is to provide safety means against oxygen-poisoning in breathing apparatus of the closed-circuit type in which a supply of pure oxygen is normally fed into the breathing gas.

A further object is to provide an auxiliary supply of breathing gas normally held in reserve, for diluting said oxygen in the breathing apparatus in the event of encountering symptoms of the beginning of oxygen-poisoning, or for replacing said oxygen supply in case of sudden failure or exhaustion of said oxygen supply.

A further object is to provide a disposable cartridge or capsule in this auxiliary supply of breathing gas which will supply "a suitable amount of additional buoyancy to assist the breather in a quick ascent to the surface of the water, in an emergency, when this auxiliary supply of breathing gas is released from the cartridge, thus serving as a double safety feature: first in preventing oxygenpoisoning by diluting the oxygen in the breathing apparatus, and second in enabling a quick return to the Water surface by increasing the buoyancy and in maintaining the breather afloat and available to rescuers if needed.

A further object is to use oxygen in the capsules as the auxiliary supply for use in emergencies resulting from sudden failure or exhaustion of the normal oxygen supply to the breathing apparatus.

A further object is to use a suitable mixture of oxygen with an inert gas such as helium or nitrogen in the capsules as an auxiliary supply of breathing gas for use in emergencies resulting either from a sudden failure as mentioned above, or encountering symptoms of oxygenpoisoning which is a result of a tendency of the body to absorb a greater amount of oxygen then it can use in the breathing process.

A further object is to use a suitable inert gas like helium in the capsules, for use in emergencies resulting from an accidental excessive feed of the normal oxygen supply, producing signs of oxygen-poisoning.

A further object is to provide a selectively biased pressure relief valve for the breathing chamber for normally maintaining a substantially balanced buoyancy of the apparatus, and during emergencies to provide a substantially greater bias to maintain a maximum buoyancy by causing the breathing chamber to expand abnormally until a higher imbalance of internal and external pressure is attained as determined by the greater valve bias.

Other and more specific objects will become apparent in the following detailed description of one form of the invention as illustrated in the accompanying drawings, wherein;

ice

Figure 1 is a general outside appearance of one form breathing apparatus equipped with the improvements of the present invention.

Figure 2 is an enlarged detail sectional view of the auxiliary gas capsule attachment and operating means.

Figure 3 is a detail sectional view taken on the line 3-3of Figure 2.

Figure 4 is a plan view of the apparatus indicating by arrows the schematic flow of the gases, and

Figure 5 is an enlarged detail sectional view of the selectively biased pressure relief valve.-

The breathing apparatus comprises the breathing bag 10 which may be made of a durable, lightweight rubberized material, in the form of substantially a rectangle, with a central cut-out portion to pass over the head for carrying it on the shoulders, its ends hanging over the chest and back of the breather.

This bag is divided axially into right and left compartments 11 and 12 extending its full length; one of these compartments comprising the inhaling or, in the present instance, the right half of the bag 11, and the other the exhaling or left half 12.

A canister 13 having open ends and'filled with a carbon dioxide absorbent material'is mounted in the rear portion of the bag and provides substantially free passage for the gases in the bag from the side 12 to the side 11. Conventional conduits 14 and 15 are provided between the compartment 11 and the mouth piece 16 for the inhaled and exhaled gas respectively, one way check valves being provided therein for controlling this directional flow, as shown by the arrows schematically in Figure 4.

The usual relief valve 17 may be provided on the exhaling conduit 15 for exhaling directly into the water when desired. An additional pressure relief and control valve 18 may be provided in the front wall of the inhaling side 11 of the bag, with a selective control to provide low or high pressure differential between the inside and outside of 'the bag, at will. A flexible annular flap valve element 18 is held fixed at its outer periphery to the valve housing, its inner edge forming a movable lip normally biased axially inwardly into closed position by a light spring 19. A second stiffer spring 20 provides a greater bias when its retainer sleeve 21 is pressed inwardly and locked against the outer end of spring 20. by means of partialthread cams 22 on the outside of sleeve 21 co'acting with complementary internal thread cams 23 on the valve housing cover 24. Lock-ring 25 normally keeps the sleeve 21 from falling out of the bore in cover 24, while permitting valve 18 to. open against the bias of the light spring 19 without interfering with the free movement of the stiff spring 25 causedby. the valve opening.

The spring 19 may be made adjustable'or may be preadjusted to retain a proper pressure differential between the breathing chamber and the outside so as to provide desired gas volume in said chamber and for normal buoyancy requirements. The stiffer spring 20 is designed to maintain a greater volume of gas in the chamber so as to obtain additional buoyancy during emergencies, when assistance in ascending to the surface of the water is desired. In such cases, the sleeve 21 is simply pressed in and turned into locking position against the stiff spring 20, and the additional gas is supplied from the emergency capsule 26, by pulling the end of the cam lever 27 downwardly. The cam depresses-the sharp pointed pin 28-so as to puncture the end of the capsule and release the gas compressed therein. This gas is directed through the passages 29 in the capsule holder 30 and mounting fitting 31, into the exhaling portion 12 of the bag.

The capsules may be expendable and have a threaded neck portion 32 for mounting in the fitting 31. A lock screw 33 may be provided in the fitting 31 as shown in Figure 2 for securing the capsule against accidental loosening when mounted.

The gas supplied in these capsules under pressure may be air of/or any other suitable mixture of oxygen with diluting gases such as nitrogen, helium etc. to provide a desired breathing mixture. Such mixture may be used to provide safety against either a sudden failure of the normal oxygen or oxygen-poisoning because it will replace the needed breathing mixture in the event of failure of the oxygen supply, and will also dilute the excess supply of oxygen in case of oxygen-poisoning prevention.

Of course, if safety against oxygen-poisoning is of prime consideration, these emergency capsules may contain only the diluting gas instead of a breathing mixture of oxygen therewith. With capsules of this kind, better dilution of the oxygen would be more readily obtained, in case of oxygen-poisoning prevention; but in case of oxygen supply failure, such diluting gas would only be useful in assisting a quick ascent and flotation on the surface of the Water, where the atmosphere would be relied on for the essential restoration of breathing gas supply.

On the other hand, if safety against failure or unexpected depletion of the oxygen in the normal supply is of primary concern, instead of possible but not so probable oxygen-poisoning, the capsules used for the emergency supply in this apparatus may be filled with a somewhat rich oxygen mixture with enough excess oxygen to 'replenish the charge of depleted breathing gas left 1n the bag, so that substantially normal over-all breathing gas will result when the capsule charge is released and the valve 18 set for the higher pressure relief, whereby most of the resulting mixture will be retained in the bag adding considerably to its buoyancy. Thus a measure of safety even against oxygen-poisoning would also be obtained in this case because of the assistance rendered by this buoyancy in reaching the surface of the water quickly and in keeping the breather afloat where rescue operations could be further administered.

It will be noted that the emergency gas is applied to ,the exhaling side 12 of the bag, and the pressure relief inflating the bag.

The manual relief valve 17 may be used by the diver at the time of discharge of the emergency cartridge and held open to prevent excess pressure forcing the mouthpiece out of the divers mouth.

The breathing bag may be provided with hold down straps 34 and 35 fixed along the axis of the bag and extending downwardly for passing under the crotch of the breather and fastening together in a conventional fashion by a buckle or hook and loop connection 36. The normal supply of oxygen may be provided by a storage tank 37 through a conventional feed control valve 38, into the exhaling side 12 of the bag.

It is not believed necessary to go into the details of normal operation of this closed circuit type of breathing apparatus, except to say that there is a danger of oxygen poisoning as a result of the tendency of oxygen under pressure, to be absorbed by the body at a rate faster than it is being used up in the breathing process, whereby the partial pressure of the oxygen content becomes dangerously excessive which ultimately leads to oxygen poisoning causing strychnine-like effects upon the nervous 1 and muscular systems of the human body.

These effects ,4 of oxygen toxicity are normally preceded by symptoms which give prior warning of this condition; and some of these warning symptoms are nervousness, twitching, headaches, and nausea. Also, if the breathing medium with the excess oxygen is promptly changed to another life sustaining gas mixture, such as an oxygen nitrogen or oxygen-helium mixture having a lower partial pressure of oxygen, the more serious results of oxygen-poisoning, such as convulsions and possible death will be averted, and the warning symptoms will disappear. Furthermore, the latent period of tolerance will be considerably extended.

This invention not only supplies the antidotal gas in a convenient and practical manner, but provides for increased inflation of the breathing bag to secure added buoyancy enabling a quick ascent to and flotation on the surface of the water where safe rescue operations might be completed. Of course, even if any other emergency arose requiring immediate return to the surface of the water, this emergency gas supply would provide the bene- ,ficial buoyancy for a quick ascent and flotation.

Thus the present invention provides safety means against a sudden failure of oxygen supply, as well as an overdose thereof, or any other emergencies which might require either a supplemental supply or dilution of the oxygen supply with or without a prompt return to and flotation on the surface of the water.

Although only one form of the invention is illustrated in the drawings, it will be obvious that the emergency cylinder of the instant invention may be utilized with a wide variety of other types of closed circuit breathing apparatus and may if desired be employed alone for use with a face mask and without other oxygen or air supply apparatus.

It will then be obvious that many modifications in the details and arrangement of the parts may be made without departing from the spirit and scope of the present invention, as defined in the appended claims.

Nhat is claimed is:

1. In a breathing bag system having portions of the bag adapted to hang over the chest and back of the breather and divided axially into inhaling and exhaling compartments a carbon-dioxide absorbing canister at the rear end of the bag in communication between the two compartments, and flexible inhaling and exhaling conduits between the corresponding shoulder portions of said compartments and a common mouthpiece; the combination of an oxygen reservoir and supply control valve means on the front of said bag supplying oxygen into the exhaling side of said system, an emergency capsule of compressed gas connected for supplying a charge of breathing gas into the front of said exhaling compartment, a pressure relief valve on the front of the inhaling compartment for maintaining a predetermined normal maximum pressure differential in the bag over the outside pressure, a holder for said capsule mounted on the front wall of said compartment having a gas receiving chamber and a passage connecting it with said compartment, a retractable biased pin extending into said chamber, and external means on said holder for depressing said pin to puncture the end of said capsule for releasing said gas into said exhaling compartment, whereby the gas in said bag may be driven out through said pressure relief valve and be substantially replaced by the emergency gas.

2. The combination of claim 1 wherein there is provided an additional manually operable relief valve adjacent said mouth piece.

3. The combination of claim 1 wherein the breathing bag system is of the closed-circuit type.

4. The combination of claim 1, wherein said pressure relief valve is provided with a quickly adjustable increased pressure bias for maintaining a predetermined abnormal maximum pressure differential so as to delay discharge from the breathing bag until a substantially increased inflation of the bag is attained to provide a substantially 9. The combination of claim 1, wherein in said emerincreased buoyancy to facilitate a quick ascent. gency gas is helium.

5. The combination of claim 1, wherein said emer- 10. The combination of claim 1, wherein said emergency gas is a breathing gas having an oxygen content gency gas is oxygen. substantially like that of air. 5

6. The combinating of claim 5, wherein said breathing R ferences Cited in the file of this patent gas is air.

7. The combination of claim 5, wherein said breathing FOREIGN PATENTS gas is an oxygen-nitrogen mixture. 630,053 Germany 21, 1939 8. The combination of claim 5, wherein said breathing 10 415,435 Italy 1946 gas is an oxygen-helium mixture. 

